The first thing you need to know about this problem is that delta total = delta Hf products - delta Hf reactants.
Delta total = (4*NO + 6*H2O) - (5*O2 + 4*NH3)
Delta total = [(4*91.3 kJ/mol) + (6*-241.8 kJ/mol.) - (5*0 kJ/mol.) + (4*-45.9 kJ/mol.)
Products= 4*(365.2)+(-1450.8)=-1085.6 kJ
Reactants=4*(-45.9) + 5*(0)= -183.6 kJ
Delta Rxn= (-1085.6 kJ) - (-183.6 kJ) =-902.0 kJ
I would say that the density increases because the distance between the molecules decreases, and therefore becomes smaller, and vice versa the density increases, and that is a physical change not a chemical change.
It is classified as a noble gas
Potassium itself is not a compound, it’s an element. Represented by “K” and has an atomic number of 19. However, it can be used to make a compound
<span>2.28 kg x 213 kJ/kg = 486 kJ = 4.86E+05 J</span>